A plurality of known production and machine tool applications do not always demand a dynamic supply of power while the corresponding application is in operation. Thus it may well occur that during specific phases of production or of the application a largely constant high torque with corresponding largely constant drive speed is demanded, while in other process phases the dynamic power supply mentioned at the outset is demanded for a varying speed. The last-mentioned phases often exhibit a lower demand for torque than those with a constant drive speed. To distinguish between them, such phases are referred to in this document as the “dynamic phase” (DP) or the “quasi-stationary phase” (QSP).
Known drive apparatuses, especially drive apparatuses for servo presses, typically comprise a synchronous motor, by means of which a required mechanical power is provided for a respective production process, with the synchronous motor being driven by an asynchronous machine via a converter. This type of known apparatus can consequently be implemented during all production phases of operation controlled by a converter, and the converter provides the power required during each operating phase in each case.
The disadvantage in such cases is that the converter has to be tuned to the highest power demanded by the drive apparatus and must be in a position to supply this highest power demanded.